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cookfp(1)              DragonFly General Commands Manual             cookfp(1)


NAME

       cookfp - calculate file fingerprint


SYNOPSIS

       cookfp [ option...  ][ filename...  ]
       cookfp -Help
       cookfp -VERSion


DESCRIPTION

       The cookfp program is used to calculate the fingerprints of files.  A
       fingerprint is a hash of the contents of a file.  The default
       fingerprint is cryptographically strong, so the probability of two
       different files having the same fingerprint is less than 1 in 2**200.

       The fingerprint is based on Dan Berstien <djb@silverton.berkeley.edu>
       public domain fingerprint 0.50 beta package 930809, posted to the
       alt.sources newsgroup.  This program produces identical results; the
       expected test results were generated using Dan's package.

       The fingerprint is a base-64-sanely-encoded fingerprint of the input.
       Imagine this fingerprint as something universal and permanent.  A
       fingerprint is 76 characters long, containing the following:

       1.  A Snefru-8 (version 2.5, 8 passes, 512->256) hash.  (Derived from
           the Xerox Secure Hash Function.)

       2.  An MD5 hash, as per RFC 1321.  (Derived from the RSADSI MD5
           Message-Digest Algorithm.)

       3.  A CRC checksum, as in the new cksum utility.

       4.  Length modulo 2^40.

       The output format is not expected to be compatible with anything.
       However, options are available to produce the purported output of
       Merkle's snefru program, the purported output of RSADSI's mddriver -x,
       or the purported output of the POSIX cksum program.

       If no files are named as input, the standard input will be used.  The
       special file name ``-'' is understood to mean the standard input.


OPTIONS

       The following options are understood:

       -Checksum
               Print the CRC32 checksum and length of the named file(s).

       -Identifier
               Print a condensed form of the fingerprint (obtained by
               performing a CRC32 checksum on the full fingerprint described
               above - a definite overkill).  This is an 8-digit hexadecimal
               number, useful for generating unique short identifiers out of
               long names.  The first character is forced to be a letter (g-
               p), so there is no problem in using the output as a variable
               name.

       -Help
               Provide some help with using the cookfp program.

       -Message_Digest
               Print the RSA Data Security, Inc. MD5 Message-Digest Algorithm
               hash of the named file(s).

       -Snefru Print the Snefru hash of the named file(s), derived from the
               Xerox Secure Hash Function.

       -VERSion
               Print the version of the cookfp program being executed.

       All other options will produce a diagnostic error.

       All options may be abbreviated; the abbreviation is documented as the
       upper case letters, all lower case letters and underscores (_) are
       optional.  You must use consecutive sequences of optional letters.

       All options are case insensitive, you may type them in upper case or
       lower case or a combination of both, case is not important.

       For example: the arguments "-help", "-HEL" and "-h" are all interpreted
       to mean the -Help option.  The argument "-hlp" will not be understood,
       because consecutive optional characters were not supplied.

       Options and other command line arguments may be mixed arbitrarily on
       the command line.

       The GNU long option names are understood.  Since all option names for
       cookfp are long, this means ignoring the extra leading '-'.  The
       "--option=value" convention is also understood.


EXIT STATUS

       The cookfp command will exit with a status of 1 on any error.  The
       cookfp command will only exit with a status of 0 if there are no
       errors.


COPYRIGHT

       cookfp version 2.30
       Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
       1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Peter
       Miller;
       All rights reserved.

       The cookfp program comes with ABSOLUTELY NO WARRANTY; for details use
       the 'cookfp -VERSion License' command.  This is free software and you
       are welcome to redistribute it under certain conditions; for details
       use the 'cookfp -VERSion License' command.


AUTHOR


       Peter Miller   E-Mail:   millerp@canb.auug.org.au
       /\/\*             WWW:   http://www.canb.auug.org.au/~millerp/

       Portions of this program are derived from sources from other people,
       sometimes with liberal copyrights, and sometimes in the public domain.
       These include:

       Dan Bernstien
               See common/fp/README for details.

       Gary S Brown.
               See common/fp/crc32.c for details.

       RSA Data Security, Inc.
               See common/fp/md5.c for details.

       Xerox Corporation
               See common/fp/snefru.c for details.

       In addition to the above copyright holders, there have been numerous
       authors and contributors, see the named files for details.  Files names
       are relative to the root of the cook distribution.

Reference Manual                     Cook                            cookfp(1)

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